Devices and Methods for Tissue Engineering

Abstract

A bioactive tissue scaffold is fabricated from glass fiber that forms a rigid three-dimensional porous matrix having a bioactive composition. Porosity in the form of interconnected pore space is provided by the pore space between the glass fiber in the porous matrix. Mechanical properties such as strength, elastic modulus, and pore size distribution is provided by the three-dimensional matrix that is formed by bonded overlapping and intertangled fibers. The bioactive tissue scaffold can be formed from raw materials that are not bioactive, but rather precursors to bioactive materials. The bioactive tissue scaffold supports tissue in-growth to provide osteoconductivity as a resorbable tissue scaffold, used for the repair of damaged and/or diseased bone tissue.

1 . A method of fabricating a synthetic bone prosthesis comprising:
 mixing a glass fiber with a bonding agent, a pore former, and a liquid to provide a plastically formable batch, the glass fiber and the bonding agent having a composition that is a precursor to a bioactive composition;   mixing the plastically formable batch to distribute the glass fiber with the bonding agent and the pore former, to provide a formable batch of a homogeneous mass, the glass fiber being arranged in an overlapping and intertangled relationship;   forming the formable batch into a desired shape to provide a shaped form;   drying the shaped form to remove substantially all the liquid;   removing the pore former; and   heating the shaped form to react the glass fiber with the bonding agent to form a porous fiber scaffold having the bioactive composition.   
     
     
         2 . The method according to  claim 1  wherein the bonding agent comprises a calcium oxide. 
     
     
         3 . The method according to  claim 1  wherein the bonding agent comprises a phosphate. 
     
     
         4 . The method according to  claim 1  wherein the bonding agent comprises a mixture of a calcium oxide and a phosphate. 
     
     
         5 . The method according to  claim 1  wherein the glass fiber comprises a silica glass fiber. 
     
     
         6 . The method according to  claim 1  wherein the glass fiber comprises calcium-silicate fiber with a calcium oxide content less than 30% by weight. 
     
     
         7 . The method according to  claim 1  wherein the glass fiber comprises a phosphate glass fiber. 
     
     
         8 . The method according to  claim 1  wherein the bonding agent comprises a coating on the glass fiber. 
     
     
         9 . A method of fabricating a synthetic bone prosthesis comprising:
 mixing at least two precursors to provide a uniform mixture, at least one of the at least two precursors in a fiber form; and   heating the uniform mixture to react the at least two precursors to form a bioactive composition, the bioactive composition having a fibrous structure.   
     
     
         10 . The method according to  claim 9  wherein the precursor in fiber form is a silica glass fiber. 
     
     
         11 . The method according to  claim 9  wherein the precursor in fiber form is a phosphate glass fiber. 
     
     
         12 . The method according to  claim 9  wherein the at least two precursors comprise oxides of magnesium, sodium, potassium, calcium and phosphorus. 
     
     
         13 . The method according to  claim 9  wherein the at least two precursors comprise a fiber having at least one of a calcium silicate and a magnesia silicate. 
     
     
         14 . The method according to  claim 9  wherein the at least two precursors comprise calcium silicate fiber and magnesia silicate fiber. 
     
     
         15 . A method of fabricating a bioactive synthetic bone prosthesis comprising:
 providing a fiber having a composition having a low level of bioactivity;   providing a precursor of a composition;   creating a rigid porous scaffold using the fiber;   altering the composition of the rigid porous scaffold using the precursor to provide a fibrous scaffold having a level of bioactivity greater than the fiber.   
     
     
         16 . The method according to  claim 15  wherein the precursor of a composition is applied to the fiber. 
     
     
         17 . The method according to  claim 15  wherein the precursor of a composition is included in the fiber. 
     
     
         18 . The method according to  claim 15  wherein the precursor of a composition is provided after the step of creating a rigid porous scaffold.